Ultrasound diagnostic equipment

0001This application is a U.S. National Phase Application under 35 USC 371 of International Application PCT/JP2011/054100 filed Feb. 24, 2011.

TECHNICAL FIELD OF THE INVENTION

0002The present invention relates to an ultrasound diagnostic equipment which transmits an ultrasound signal toward an inner part of a subject and generates an ultrasound image of the inner part of the subject based on a reflective wave.

PRIOR ART

0003An ultrasound wave usually represents a sound wave of 16000 Hz or more, and is applied to various fields such as a defect inspection and a diagnosis of diseases, because the inner parts can be checked non-destructively, harmlessly and in approximately real time. As one of such applications, an ultrasound diagnostic equipment carries out an ultrasound imaging of an internal state of a subject based on the received signal generated from the reflective wave of the ultrasound wave from the inner part of the subject by allowing an ultrasound probe scan the inner part of the subject. The ultrasound diagnostic equipment is relatively low in cost and small compared with other imaging equipments for medical use, and is high in safety because no radiation of X-rays and so on is irradiated. Further, it has various features such that it is possible to obtain medical images such as B mode images by performing an envelope curve detection processing to the reflective wave of the ultrasound wave. For this reason, the ultrasound diagnostic equipment is widely used by circulatory organ systems (for example, coronary arteries of the heart and so on.), digestive systems (for example, stomach and intestines and so on.), the internal medicine system (for example, liver, pancreas, spleen, and so on.), urinary-organs systems (for example, the kidney, a bladder, and so on.), an obstetrics-and-gynecology system, and so on.

0004On an ultrasound image, the speckle pattern resulting from a random interference of the ultrasound wave may be generated. Although the speckle pattern is used for diagnosis of liver cirrhosis and so on, in the case of mammography screening, there is a close resemblance between the speckle pattern and a minute structure such as a microcalcification, and the speckle pattern will be a confusing image information in the mammography screening. There is a request of wanting to improve the accuracy of a medical checkup by extracting and removing the speckle pattern in mammography screening and so on.

0005As a technology for encountering this, there is technology for removing a speckle pattern from the ultrasound image information, distinguishing a minute structure such as a microcalcification from a continuation structure, by a two-dimensional or three-dimensional continuity and extracting the minute structure (for example, refer to patent document 1).

0006Further, there is a technology of acquiring an echo level probability-density-distribution information on the speckle pattern obtained as a result of the mutual interference of a Rayleigh dispersion, and acquiring organization behavior information by a gap from the Rayleigh distribution of the distribution curve (for example, refer to patent document 2).

PRIOR TECHNICAL DOCUMENTS

Patent Documents

0000[Patent document 1] Japanese Unexamined Patent Application Publication 2007-268155

0000[Patent document 2] Japanese Unexamined Patent Application Publication 2001-238884

SUMMARY OF THE INVENTION

Problems to be Solved by the Present Invention

0007The technology described in the patent document 1 is a method for extracting a minute structure from ultrasound image information in image processing, and the extraction processing is performed only from the image-informatized information, the information in respect to the size about the minute scattered object smaller than a sound ray pitch is not acquired. Further, when microcalcifications exist continuous within a mammary duct, it is difficult to distinguish the calcifications from continuation structures, such as organizational boundaries, and it may be unable to extract the calcifications.

0008In the technology described in the patent documents 2, a state of a certain whole region is judged by processing statistically image information such as a speckle pattern obtained from the result of the mutual interference of Rayleigh dispersion, and it is difficult to extract extraction structures such as a microcalcification.

0009An object of the present invention is to supply the ultrasound diagnostic equipment which is capable of extracting even microcalcifications which exist continuously by transmitting sound waves having a wide band frequency and calculating of particle radii of particle bodies by the difference in frequency component ratios in the reflective ultrasound wave, and is capable of acquiring the particle radii of the particle bodies simultaneously.

Means to Solve the Problems

0010The above-mentioned object can be achieved by inventions described below.

00111. An ultrasound diagnostic equipment which is equipped with an ultrasound probe which transmits an ultrasound wave toward an inner part of a subject and receives the ultrasound wave reflected by a particle body in the subject and acquires a received signal to display an internal body information in the subject based on the received signal, the ultrasound diagnostic equipment comprising:

0012an acquisition section to acquire the received signal for each of ultrasound waves of which frequencies differ;

0013an intensity ratio calculation section to calculate an intensity ratio by acquiring an intensity of the ultrasound wave for each of frequencies from the acquired received signal for each of the ultrasound waves; and

0014a display section to display an information on the intensity ratio.

00152. The ultrasound diagnostic equipment described in the item 1, comprising a particle radius calculation section to calculate a particle radius of the particle body based on the information on the intensity ratio which the intensity ratio calculation section calculated, in place of the display section. <br /> 3. The ultrasound diagnostic equipment described in the item 2, comprising a display section to display the particle radius calculated by the particle radius calculation section. <br /> 4. The ultrasound diagnostic equipment described in the item 2, comprising a section which extracts the particle body which has the particle radius of a range specified automatically or arbitrarily based on a calculation result of the particle radius calculation section and carries out imaging of the particle body. <br /> 5. The ultrasound diagnostic equipment described in any one of items 1 thorough 4, wherein the ultrasound probe has a −20 dB fractional bandwidth which is not less than 80%. <br /> 6. The ultrasound diagnostic equipment described in any one of items 1 thorough 5, wherein the ultrasound probe includes a piezo-electric element which transmits a ultrasound wave and a transmitting section which drives the piezo-electric element, wherein the transmitting section drives the piezo-electric element by a burst wave of a rectangular wave of a duty cycle not more than of 0.3. <br /> 7. The ultrasound diagnostic equipment described in any one of items 1 thorough 5, wherein the ultrasound probe transmits the ultrasound wave of a plane wave.

Effects of the Invention

0016The ultrasound diagnostic equipment which is capable of extracting even the microcalcifications which exist continuously and, at the same time, is capable of grasping the particle radii of particle bodies is provided.

BRIEF DESCRIPTION OF THE DRAWINGS

<figref idref="DRAWINGS">FIG. 1</figref> is a schematic drawing showing an appearance composition of the ultrasound diagnostic equipment relating to an embodiment.

<figref idref="DRAWINGS">FIG. 2</figref> is a block diagram showing an electric composition of the ultrasound diagnostic equipment relating to the embodiment.

<figref idref="DRAWINGS">FIG. 3</figref> is a schematic drawing showing the composition of the ultrasound probe of the ultrasound diagnostic equipment relating to the embodiment.

<figref idref="DRAWINGS">FIG. 4</figref> is an example of a voltage waveform of the drive electric signal.

<figref idref="DRAWINGS">FIG. 5</figref> shows the calculation result of a spectrum in the drive electric signal of <figref idref="DRAWINGS">FIG. 4</figref> which the transmitting section <b>12</b> generated.

<figref idref="DRAWINGS">FIG. 6</figref> is a typical diagram showing an example of a band width characteristic in the transmission and reception of the ultrasound probe <b>2</b>.

<figref idref="DRAWINGS">FIG. 7</figref> is a figure showing a frequency spectrum of a sound pressure of the first ultrasound wave signal when the transmitting signal shown in <figref idref="DRAWINGS">FIG. 4</figref> is inputted to the ultrasound probe <b>2</b>.

<figref idref="DRAWINGS">FIG. 8</figref> is a figure showing a relation of Z function of Stenzel and k·a.

<figref idref="DRAWINGS">FIG. 9</figref> is an electric block diagram showing the details of the signal processing section <b>14</b>.

<figref idref="DRAWINGS">FIG. 10</figref> is a typical diagram showing an example of the ultrasound image for each particle radius.

<figref idref="DRAWINGS">FIG. 11</figref> is a typical diagram showing the relation between the first ultrasound wave signal transmitted from the ultrasound probe <b>2</b>, and a particle body.

DETAILED DESCRIPTION OF THE INVENTION

0028Although the embodiment of the invention is explained below with drawings, the present invention is not restricted to the embodiment explained below. Further, the composition to which the same mark is attached in each figure represents the same composition, and the explanation is omitted.

0029<figref idref="DRAWINGS">FIG. 1</figref> is a schematic drawing showing the appearance composition of the ultrasound diagnostic equipment relating to the embodiment. <figref idref="DRAWINGS">FIG. 2</figref> is a block diagram showing the electric composition of the ultrasound diagnostic equipment relating to an embodiment. <figref idref="DRAWINGS">FIG. 3</figref> is a schematic drawing showing the composition of the ultrasound probe of the ultrasound diagnostic equipment relating to an embodiment.

0030As shown in <figref idref="DRAWINGS">FIGS. 1 and 2</figref>, the ultrasound diagnostic equipment S is configured by comprising an ultrasound probe <b>2</b> which transmits an ultrasound signal (it is also henceforth called a first ultrasound wave signal) to the subject H such as a living body (not shown), and receives a reflective wave (it is also henceforth called a second ultrasound wave signal) of the ultrasound signal reflected by subject H, and an ultrasound diagnostic equipment main body <b>1</b> which connects with the ultrasound probe <b>2</b> through a cable <b>3</b>, makes the ultrasound probe <b>2</b> transmit the first ultrasound wave signal to the subject H by transmitting the transmitting signal of an electric signal to the ultrasound probe <b>2</b> through a cable <b>3</b>, and carries out imaging to a medical image by making the internal state in the subject H into an ultrasound image based on the received signal of the electric signal generated by the ultrasound probe <b>2</b> according to the second ultrasound wave signal received by the ultrasound probe <b>2</b> from the subject H. The ultrasound diagnostic equipment main body <b>1</b> is equipped with an ultrasound probe holder <b>4</b> which holds the ultrasound probe <b>2</b> when the ultrasound probe <b>2</b> is not used.

0031As shown in <figref idref="DRAWINGS">FIG. 2</figref>, for example, the ultrasound diagnostic equipment main body <b>1</b> is constituted by comprising an operation input section <b>11</b>, a transmitting section <b>12</b> and receiving section <b>13</b> of the present invention, a signal processing section <b>14</b> of the present invention, an image processing section <b>15</b>, a display section <b>16</b>, a control section <b>17</b>, and a memory section <b>19</b>.

0032The operation input section <b>11</b> through which, for example, a command to direct a diagnostic start and data such as a personal information on the subject H are inputted, is an operation panel equipped with plural switches or a keyboard and so, for example.

0033The transmitting section <b>12</b> of the present invention supplies the transmitting signal through the cable <b>3</b> to the piezo-electric section <b>32</b> in the ultrasound probe <b>2</b>, and makes the ultrasound probe <b>2</b> generate the first ultrasound wave signal. The transmitting section <b>12</b> is constituted by equipping with a high voltage pulse generator which generates a high voltage pulse, for example, and makes the ultrasound probe <b>2</b> transmit the first ultrasound wave signal which has harmonics frequency components other than a fundamental frequency component to the subject H. The details are explained later.

0034Further, the piezo-electric section <b>32</b> may consist of two piezo-electric sections which are a piezo-electric section for transmission and a piezo-electric section for reception.

0035The receiving section <b>13</b> is a circuit which receives the received signal of an electric signal through the cable <b>3</b> from the ultrasound probe <b>2</b> according to the control of the control section <b>17</b>, and outputs this received signal to the signal processing section <b>14</b>. The receiving section <b>13</b> is constituted by equipping with the amplifier which amplifies a received signal at the predetermined amplification rate which has been set up beforehand, for example, an analog-to-digital converter which converts the received signal amplified by the amplifier from an analog signal into a digital signal, and so on.

0036The signal processing section <b>14</b> of the present invention is a circuit which performs a predetermined signal processing to the electric signal from the receiving section <b>13</b>, according to the control of the control section <b>17</b>, and outputs the reflective received signal subject to a predetermined signal processing, to the image processing section <b>15</b>. The reflective signal includes a reflective signal based on the fundamental frequency component and the harmonic frequency component which the transmitting section <b>12</b> generated, and the signal processing section <b>14</b> performs a signal processing for each frequency component. The details are explained later.

0037The image processing section <b>15</b> is a circuit which generates the ultrasound image of the internal state in the subject H using a harmonic imaging technology and so on based on the reflective received signal to which the signal processing was performed in the signal processing section <b>14</b> according to the control of the control section <b>17</b>. For example, B mode signal corresponding to an amplitude intensity of the second ultrasound wave signal is generated by performing an envelope curve detection processing to the reflective received signal.

0038The memory section <b>19</b> is constituted by comprising RAM or ROM. A program used for the control section <b>17</b> and a template of the various images to be displayed in the display section <b>16</b> are recorded in the memory section <b>19</b>.

0039The display section <b>16</b> is an equipment which displays a synthetic image synthesized in the image synthesizing section <b>18</b> according to the control of the control section <b>17</b> as an internal body information. The display section <b>16</b> is a display device such a CRT display, an LCD, an EL display, a plasma display, and so on, or a printing device such as a printer, for example.

0040The control section <b>17</b> is a circuit which is configured by equipping, for example, a microprocessor, a storage device, a peripheral circuit thereof, and so on, and performs a whole control of the ultrasound diagnostic equipment S by controlling the operation input section <b>11</b> for them, the transmitting section <b>12</b>, the receiving section <b>13</b>, the signal processing section <b>14</b>, the image processing section <b>15</b>, the image synthesizing section <b>18</b>, and the memory section <b>19</b> corresponding to each of the functions.

0041On the other hand, the ultrasound probe <b>2</b> is equipped with the transducer <b>30</b>. The transducer <b>30</b> transmits the first ultrasound wave signal to the subject H, such as a living body (not shown in the drawing), and receives the second ultrasound wave signal from the subject H. The transducer <b>30</b> is constituted by having, for example, an acoustic inhibiting member <b>31</b>, a piezo-electric section <b>32</b>, a sound adjustment layer <b>33</b>, and an acoustic lens <b>34</b> as shown in <figref idref="DRAWINGS">FIG. 3</figref>.

0042The acoustic inhibiting member <b>31</b> is a plate shaped member consisted of material absorbing an ultrasound wave, and absorbs the ultrasound wave emitted toward the acoustic inhibiting member <b>31</b> from the piezo-electric section <b>32</b>.

0043The piezo-electric section <b>32</b> is constituted by having a piezo-electric material and transduces a signal mutually between an electric signal and an ultrasound signal by using a piezo-electric phenomenon. The piezo-electric section <b>32</b> transduces the electric signal of the transmitting signal inputted through the cable <b>3</b> from the transmitting section <b>12</b> of the ultrasound diagnostic equipment main body <b>1</b> into the first ultrasound wave signal to transmit the first ultrasound wave signal, and outputs the received signal which is an electric signal to which the received second ultrasound wave signal is transduced, to the receiving section <b>13</b> of the ultrasound diagnostic equipment main body <b>1</b> through the cable <b>3</b>. When the ultrasound probe <b>2</b> is contacted to the subject H, the first ultrasound wave signal generated in the piezo-electric section <b>32</b> is transmitted into the subject H, and the second ultrasound wave signal from the subject H is received by the piezo-electric section <b>32</b>.

0044The piezo-electric section <b>32</b>, for example, in the present embodiment, is constituted by having a piezo-electric material and can employ a common piezo-electric materials such as lead zirconate titanate which can change a signal mutually between an electric signal and an ultrasound signal by using a piezo-electric phenomenon. Other than this, an organic piezo-electric material such as a polymer of vinylidene fluoride, and the copolymer of vinylidene fluoride and trifluoroethylene, for example, can be used. Since the electromechanical coupling coefficient (piezo-electric effect) in the thickness direction changes with copolymerization ratios in the case of the copolymer of vinylidene fluoride and trifluoroethylene, for example, the copolymerization ratio of 60-99 mol % is desirable. Further, such organic piezo-electric materials are suitable as a piezo-electric material which has the high frequency characteristic and the broadband characteristic.

0045With this embodiment, the electric signal is inputted through the cable <b>3</b> from the transmitting section <b>12</b> of the ultrasound diagnostic equipment main body <b>1</b>, and the piezo-electric section <b>32</b> transduces the electric signal into the first ultrasound wave signal, and transmits the transduced first ultrasound wave signal to the subject H through the sound adjustment layer <b>33</b> and the acoustic lens <b>34</b>. And the piezo-electric section <b>32</b> receives the second ultrasound wave signal from the subject H through the acoustic lens <b>34</b> and the sound adjustment layer <b>33</b>, transduces the received second ultrasound wave signal into an electric signal, and outputs the transduced electric signal to the receiving section <b>13</b> of the ultrasound diagnostic equipment main body <b>1</b> through the cable <b>3</b> as a received signal.

0046Subsequently, the transmitting section <b>12</b>, the signal processing section <b>14</b>, and so on of the present invention are explained in detail.

0047The transmitting section <b>12</b> generates the drive electric signal which has not only a single frequency component but also plural frequency components of a large frequency difference as the transmitted wave used for extracting particles. <figref idref="DRAWINGS">FIG. 4</figref> shows an example of a voltage waveform of the drive electric signal. The horizontal axis expresses time and the vertical axis expresses the drive voltage.

0048The drive voltage waveform relating to the embodiment is a rectangle wave burst wave, and is a wave form of a duty cycle of 0.3 or less. A duty cycle is a ratio (B/A) of the time of a shorter rectangle which constitutes 1 cycle of the rectangle wave to the time of 1 cycle. The rectangle wave has high order frequency components by a Fourier series expansion, and the amplitude of the high order frequency can be enlarged by making the duty cycle in a rectangle wave small. That is, the rectangle wave has of a duty cycle of 0.3 or less has a wider amplitude compared with such a rectangle wave of the duty cycle of 0.5. Further, the rectangle wave shown in <figref idref="DRAWINGS">FIG. 4</figref> has a fundamental period of 5 MHz.

0049The transmitting section <b>12</b> is equipped with a high voltage pulse generator which has a known pulse generator function (not shown in drawings) which can generate this rectangle wave.

0050<figref idref="DRAWINGS">FIG. 5</figref> shows the calculation result of the spectrum in the drive electric signal of <figref idref="DRAWINGS">FIG. 4</figref> which the transmitting section <b>12</b> generated. A horizontal axis expresses frequency and a vertical axis expresses the drive voltage displaying relatively with dB.

0051The drawing shows that, other than 5 MHz component, frequency components which correspond 2 to 4 times of the frequency are included. Further, since the drive electric signal is a burst wave, the drive electric signal has a short frequency component below the fundamental frequency based on an envelope curve, and the satellite frequency component has occurred between the harmonic waves based on the short frequency component and the harmonics components.

0052Further, the ultrasound probe <b>2</b> has the frequency characteristic of the ultrasound probe itself. <figref idref="DRAWINGS">FIG. 6</figref> is a typical diagram showing an example of the band characteristic in transmission and reception of the ultrasound probe <b>2</b>. That is, the frequency characteristic of the amplitude value of the sound pressure of the first ultrasound wave signal to transmit is expressed. In the drawing, the bandwidth of which an amplitude value falls by −20 dB is set to D, the center value of the band set to C, and −20 dB ratio bandwidth is defined as D/C.

0053<figref idref="DRAWINGS">FIG. 7</figref> expresses the frequency spectrum of the sound pressure of the first ultrasound wave signal when the transmitting signal shown in <figref idref="DRAWINGS">FIG. 4</figref> is inputted to the ultrasound probe <b>2</b> which has the frequency characteristic like this.

0054The frequency spectrum of the sound pressure of the first ultrasound wave signal becomes a multiplication of the frequency characteristics of the transmitting signal and the ultrasound probe <b>2</b>.

0055Further, the transmitting section <b>12</b> performs a transmitting beam forming processing, and has a function which converges the first ultrasound wave signal on the subject.

0056Next, the signal processing section <b>14</b> of the present invention is explained in detail.

0057In the signal processing section <b>14</b>, an ultrasound image is individually generated for each frequency. Especially in the embodiment, the calculation of the particle radius of a particle body which is a microcalcification is performed in a mammography screening. In the domain of this particle radius, the dispersion characteristic is in the domain of the characteristic of Rayleigh dispersion.

0058When a sound pressure P at the position of the ultrasound probe when the particle body (reflecting body of radius a) locates at a distance x from the ultrasound probe which is a sound source and a reflective wave pressure Pr at the position of the ultrasound probe position when the rigid plane surface is located at the position of the particle body are presumed, a reflective power R which is a ratio of these can be expressed with the following formula: <br /><i>R=P/Pr=</i>2<i>aZ/x</i>  (1)

0059Where, Z is Z function of Stenzel and is shown in <figref idref="DRAWINGS">FIG. 8</figref>. In <figref idref="DRAWINGS">FIG. 8</figref>, k is ω/c, where ω is the frequency of the ultrasound wave and c is the speed of the ultrasound wave. Please refer to “Ultrasound Technical Handbook” (Nikkan Kogyo Shimbun, the fifth printing of the new edition) for details.

0060The formula leads a relation that, in the domain of Rayleigh dispersion, the particle radius a and the sound pressure P at the position of the ultrasound probe are approximately proportional. Therefore, for example, the ultrasound signal of plural frequencies is irradiated to the particle body, a frequency analysis of the second ultrasound wave signal reflected from the particle body is conducted, and the reflective power R is measured for each frequency which has been transmitted. By computing the ratio (namely, intensity ratio) of the reflective power for each frequency from the measurement result, the information on the intensity ratio can be displayed on the display section. Furthermore, the particle radius a of the reflecting body can be computed from the ratio of the reflective power for each frequency. That is, the signal processing section <b>14</b> has a function as an intensity ratio calculation section to calculate the intensity ratio by acquiring the intensity of the ultrasound wave for each frequency and calculating the intensity ratio from the acquired intensities, and a function as a particle radius calculation section to calculate the particle radius a of the reflecting body.

0061For example, the first ultrasound wave signals which have three frequencies, ω1, ω2, and ω3, respectively are transmitted to the particle body, and the reflective powers Rω1, Rω2, and Rω3 at the time when each first ultrasound wave signal is reflected with the particle body are measured. And the ratio of reflective power, i.e., the intensity ratio, is displayed on the display section <b>16</b>. Furthermore, by using the relation between reflective power R and Z function as defined in formula (1), the relation among the Z functions Zω1, Zω2, and Zω3 for each frequency is calculated as depicted in <figref idref="DRAWINGS">FIG. 8</figref>. For example, if the Z functions Zω1, Zω2, and Zω3 have a relation b<b>1</b> in <figref idref="DRAWINGS">FIG. 8</figref>, it will turn out that ω1, ω2, and ω3 have a positional relationship as shown in the drawing, and the particle radius a equivalent to the relation will become clear. Further, if Z functions Zω1, Zω2, and Zω3 have a relation b<b>2</b> in <figref idref="DRAWINGS">FIG. 8</figref>, it will turn out that ω1, ω2, and ω3 has a positional relationship as shown in the drawing, and the particle radius a equivalent to the relation will become clear.

0062This signal processing is realized by the circuit shown in <figref idref="DRAWINGS">FIG. 9</figref>. <figref idref="DRAWINGS">FIG. 9</figref> is an electric block diagram showing the details of the signal processing section <b>14</b>. The signal processing section <b>14</b> has band pass filters fn and individual signal processing sections sn (n is a natural number). The received signal from the receiving section <b>13</b> is inputted into the band pass filters f<b>1</b> through fn of n numbers which are provided in the signal processing section <b>14</b>. The band pass filter is an electric filter which passes only the electric signal of the n-th frequency, and known multiplex feedback filter which is constituted by, for example, an operational amplifier, a resistor, and a capacitor can be used. The electric signal which passed through the band pass filter fn is inputted into the individual signal processing section sn, and is subjected to an AD conversion processing, a receiving apodization processing, a phasing addition processing, an envelope curve detection processing, and so on, and the reflective power R for each frequency is measured.

0063The reflective power R for each frequency is inputted into the data processing section <b>141</b>, and the ratio of the reflective power R for each frequency is calculated. In the memory section <b>142</b>, the relation of the Z function of Stenzel and k·a shown in <figref idref="DRAWINGS">FIG. 8</figref> is memorized. Specifically, the ratios of the reflective powers Rω1, Rω2, and Rω3 and their relations to the particle radius a are memorized. The data processing section <b>141</b> deduces the particle radius a with reference to the memory section <b>142</b>.

0064Further, since the ultrasound wave of plural frequencies is transmitted with one ultrasound probe <b>2</b> as mentioned above, the relative bandwidth is preferable to be 80% or more so that the ultrasound probe <b>2</b> can transmit the ultrasound wave of plural frequencies. When the relative bandwidth is 80% or more, a large number of high order harmonics can be transmitted at once.

0065In the image processing section <b>15</b>, the ultrasound image for each particle radius is generated from the electric signal which is processed for each frequency in the signal processing section <b>14</b> and the information on the particle radius.

0066According to the control of the control section <b>17</b>, the image processing section <b>15</b> superimposes all the ultrasound images for each particle radius, or superimposes only ultrasound images of selected frequencies, and data processes the superimposed ultrasound images to input into the display section <b>16</b>. A user can selects the ultrasound image displayed on the display section <b>16</b> in the operation input section <b>11</b>. The specified range of the particle radii in the ultrasound image for each particle radius can be specified automatically or arbitrarily. Further, the range of a part or all of the ultrasound image can be specified automatically or arbitrarily to perform imaging.

0067<figref idref="DRAWINGS">FIG. 10</figref> is a typical diagram showing an example of the ultrasound image for each particle radius. The particle radius becomes smaller as it goes from <figref idref="DRAWINGS">FIG. 10 (<i>a</i>)</figref> to <figref idref="DRAWINGS">FIG. 10 (<i>d</i>)</figref>. <figref idref="DRAWINGS">FIG. 10 (<i>e</i>)</figref> shows the image which is obtained by adding all the images from <figref idref="DRAWINGS">FIG. 10 (<i>a</i>)</figref> thorough <figref idref="DRAWINGS">FIG. 10 (<i>d</i>)</figref>.

0068Further, <figref idref="DRAWINGS">FIG. 10 (<i>f</i>)</figref> shows the ultrasound image in which microcalcifications of minute particle shapes exist continuously. If the ultrasound diagnostic equipment S relating to this embodiment is used, the ultrasound image of the minute particle bodies of the microcalcification which exist continuously in this way can be generated.

0069By the way, the first ultrasound wave signal to transmit is preferable to be an approximately plane wave in order to calculate a body of a small particle radius. <figref idref="DRAWINGS">FIG. 11(<i>a</i>)</figref> is a typical diagram showing the relation between the first ultrasound wave signal transmitted from the ultrasound probe <b>2</b>, and a particle body.

0070In the ultrasound diagnosis, the first ultrasound wave signal is converged in the lateral direction to form a scanning line called a sound ray and obtain a cross-sectional image of one sheet by sequentially shifting one by one, in order to calculate the minute portion in the subject to obtain the cross-sectional image. The convergence of the lateral direction is performed generally by beam forming which changes a phase in time so that the first ultrasound wave signals which the plural piezo-electric elements prepared in the ultrasound probe <b>2</b> transmit arrive simultaneously at the point to converge. If the first ultrasound wave signals are converged as mentioned above, the first ultrasound wave signals may not be irradiated to the minute particle body <b>91</b> or the irradiation intensity may become weak, as shown in <figref idref="DRAWINGS">FIG. 11(<i>a</i>)</figref>. Then, as shown in <figref idref="DRAWINGS">FIG. 11(<i>b</i>)</figref>, it is preferable to transmit the first ultrasound wave signal of a plane or approximately plane wave so that the first ultrasound wave signal can irradiate throughout the inside of the subject.

0071Specifically, a plane wave can be transmitted by adjusting the drive times of the plural piezo-electric elements to transmit the first ultrasound wave so as to make synthetic wave faces thereof to be plane.

0072It becomes possible to eliminate the influence of the beam intensity difference of the first ultrasound wave signal of the lateral direction RD by the difference in frequency by transmitting the first ultrasound wave signal as an approximately plane wave, as mentioned above.

0073Further, in this embodiment, although high order harmonics frequencies are included other than the fundamental frequency in the first ultrasound wave signal which the ultrasound probe <b>2</b> transmits, and the plural frequencies are prepared in the first ultrasound wave signal and the ultrasound image is generated from the second ultrasound wave signal corresponding to each frequency, other configuration can be used. For example, the fundamental frequency and high order harmonic frequencies may be transmitted using at least two ultrasound probes <b>2</b>, and each ultrasound probe <b>2</b> may generate an ultrasound image from the second ultrasound wave signal. Further, for example, one ultrasound probe <b>2</b> may transmit individually the fundamental frequency and the high order harmonics frequencies in a series time in order, and an ultrasound image may be generated from each of the second ultrasound wave signals.

0074Further, in this embodiment, the cable connection or wireless connection of the ultrasound probe <b>2</b> may be made with the ultrasound diagnostic equipment main body <b>1</b>.

EMBODIMENTS

0075Hereafter, the embodiments explain specifically the present invention although the present invention is not limited to these.

0076Calcium carbonate dispersing agent is employed as the particle body and a plate of the perfect reflection body is employed as a reference. The calcium carbonate dispersing agent is dispersed in water, the transmitting side of the ultrasound probe <b>2</b> is contacted to the water, the first ultrasound wave signal is transmitted, and the reflective wave is obtained. Further, the plate is immersed in water to obtain the reflective wave similarly. The first fundamental frequency ω1, the second harmonic frequency ω2, and the third harmonics frequency ω3 are contained in the ultrasound probe <b>2</b>, each intensity in the reflective wave is calculated and the ratios of reflective powers are obtained as shown in Table 1. As shown in Table 1, the reflective wave is calculated for each particle radius by making the particle radii of the calcium carbonate dispersing agent into four classes. The reflective powers are normalized with the largest reflective power among the reflective powers of frequencies ω1 through ω3. There is no difference in the reflective power by frequency for the plate, and the reflective power is set as a reference value.

0077This result showed that the frequency dependability of reflective power became larger as the particle radius becomes smaller, and the characteristic of reflective power was acquired as shown in <figref idref="DRAWINGS">FIG. 8</figref>. For example, it turned out that, in the case of particles of 135-165 micrometers of particle radius, the reflective power of second harmonic wave ω2 was larger than that of the fundamental frequency ω1 and third harmonic wave ω3, and the state of b<b>1</b> of <figref idref="DRAWINGS">FIG. 8</figref> was shown. Further, in the case of particles of 15-25 micrometers of particle radius, it turned out that reflective power was smaller when the degree of harmonic waves was smaller, compared with the case of larger particle radius.

0078<tables id="TABLE-US-00001" num="00001"><table frame="none" colsep="0" rowsep="0"><tgroup align="left" colsep="0" rowsep="0" cols="3"><colspec colname="offset" colwidth="70pt" align="left" /><colspec colname="1" colwidth="56pt" align="center" /><colspec colname="2" colwidth="91pt" align="center" /><thead><row><entry /><entry namest="offset" nameend="2" rowsep="1">TABLE 1</entry></row></thead><tbody valign="top"><row><entry /><entry namest="offset" nameend="2" align="center" rowsep="1" /></row><row><entry /><entry>Particle Diameter</entry><entry>Ratio of Reflective power *</entry></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="5"><colspec colname="1" colwidth="70pt" align="left" /><colspec colname="2" colwidth="56pt" align="center" /><colspec colname="3" colwidth="35pt" align="center" /><colspec colname="4" colwidth="28pt" align="center" /><colspec colname="5" colwidth="28pt" align="center" /><tbody valign="top"><row><entry>Particle body</entry><entry>(μm)</entry><entry>ω1</entry><entry>ω2</entry><entry>ω3</entry></row><row><entry namest="1" nameend="5" align="center" rowsep="1" /></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="5"><colspec colname="1" colwidth="70pt" align="left" /><colspec colname="2" colwidth="56pt" align="center" /><colspec colname="3" colwidth="35pt" align="char" char="." /><colspec colname="4" colwidth="28pt" align="char" char="." /><colspec colname="5" colwidth="28pt" align="char" char="." /><tbody valign="top"><row><entry>Calcium Carbonate</entry><entry>135-165</entry><entry>0.85</entry><entry>1</entry><entry>0.89</entry></row><row><entry>Dispersing Agent</entry><entry>70-90</entry><entry>0.8</entry><entry>0.96</entry><entry>1</entry></row><row><entry /><entry>30-50</entry><entry>0.43</entry><entry>1</entry><entry>0.95</entry></row><row><entry /><entry>15-25</entry><entry>0.05</entry><entry>0.34</entry><entry>1</entry></row><row><entry namest="1" nameend="5" align="center" rowsep="1" /></row><row><entry namest="1" nameend="5" align="left" id="FOO-00001">* Ratio of Reflective power is calculated by regarding the ratio of reflective power of the reference plate as 1.</entry></row></tbody></tgroup></table></tables>

0079As mentioned above, according to the embodiment, it is possible to provide an ultrasound diagnostic equipment S equipping with an ultrasound probe <b>2</b> which transmits an ultrasound wave into the subject H and receives the ultrasound wave reflected by the particle body in the subject H to acquire a received signal; displays internal body information based on the received signal; and is capable of extracting even microcalcifications which exist continuously by having a section for acquiring the received signals of which frequencies are different by each frequency, an intensity ratio calculation section which obtains the intensities of the ultrasound wave for each frequency from the obtained received signal for each ultrasound wave to calculates the intensity ratios, and a display section to display the information on the intensity ratios.

0080Further, according to the embodiment, it is possible to provide an ultrasound diagnostic equipment in which, in place of the display section, the intensity ratio calculation section can calculate the particle radius of the particle body based on the information on the calculated intensity ratios.

0081Further, according to the embodiment, it is possible to provide an ultrasound diagnostic equipment which can display the particle radius which the particle radius calculation section calculated.

0082Further, according to the embodiment, it is possible to provide an ultrasound diagnostic equipment which can select a particle body of an arbitrarily particle radius to be extracted and carry out imaging of the particle body, as the ultrasound diagnostic equipment can have a section which extracts and carries out imaging of the particle body which has the particle radius of the range specified automatically or arbitrarily based on the calculation result of the particle radius of a particle body.

0083Further, according to the embodiment, it is possible to provide an ultrasound diagnostic equipment which can extract even microcalcifications better and at the same time, calculate the radius of a particle body better, as the ultrasound probe <b>2</b> has a −20 dB fractional bandwidth which is not less than 80% and can transmit the sound wave which contains a high frequency advantageous to resolution, and also a low frequency component of a large frequency difference

0084Further, according to the embodiment, it is possible to provide an ultrasound diagnostic equipment equipping with the ultrasound probe <b>2</b> which has the piezo-electric element which transmits an ultrasound wave and a transmitting section which drives this piezo-electric element; and can extract even microcalcifications better and, at the same time, calculates the particle radius better since the transmitting section can generate the ultrasound wave which contains many high order harmonic waves as the piezo-electric element is driven by the rectangle wave burst wave of not more than duty cycle 0.3.

0085Further according to the embodiment, it is possible to provide an ultrasound diagnostic equipment in which can extract even microcalcifications better and at the same time, calculates the particle radius better because the ultrasound probe <b>2</b> can eliminate the influence of the beam intensity difference of the ultrasound signal of the lateral direction RD by the difference in frequency by transmitting the ultrasound wave of a plane wave.

DESCRIPTION OF NUMERIC DESIGNATIONS

0000<ul id="ul0001" list-style="none"><li id="ul0001-0001" num="0000"><ul id="ul0002" list-style="none"><li id="ul0002-0001" num="0086"><b>1</b> Main body of Ultrasound Diagnostic Equipment</li><li id="ul0002-0002" num="0087"><b>2</b> Ultrasound Probe</li><li id="ul0002-0003" num="0088"><b>3</b> Cable</li><li id="ul0002-0004" num="0089"><b>4</b> Ultrasound Probe Holder</li><li id="ul0002-0005" num="0090"><b>11</b> Operation input section</li><li id="ul0002-0006" num="0091"><b>12</b> Transmitting section</li><li id="ul0002-0007" num="0092"><b>13</b> Receiving section</li><li id="ul0002-0008" num="0093"><b>14</b> Signal processing section</li><li id="ul0002-0009" num="0094"><b>15</b> Image processing section</li><li id="ul0002-0010" num="0095"><b>16</b> Display section</li><li id="ul0002-0011" num="0096"><b>17</b> Control section</li><li id="ul0002-0012" num="0097"><b>19</b> Memory section</li><li id="ul0002-0013" num="0098"><b>91</b> Particle body</li><li id="ul0002-0014" num="0099"><b>141</b> Data processing section</li><li id="ul0002-0015" num="0100"><b>142</b> Memory section</li><li id="ul0002-0016" num="0101">fn Band pass filter</li><li id="ul0002-0017" num="0102">H Subject</li><li id="ul0002-0018" num="0103">S Ultrasound diagnostic equipment</li><li id="ul0002-0019" num="0104">sn Individual signal processing section</li></ul></li></ul>